Slings are ancient devices used to launch masses. In a conventional sling, a mass to be launched is located at the end of an arm that is rotated along a circular path. Typically, the arm is made of a flexible material, such as a cord or the like.
The sling would be an effective device for accelerating masses to hypervelocities if the sling could be operated in a field-free vacuum with a long mythical cord of infinite tensile strength and small mass density. It would also be advantageous if a mass being accelerated by the sling could encounter minimum friction as in a field-free vacuum and out of contact with a track.
While certain toys have been developed base on sling principles, they are not suitable for accelerating a large mass to high velocity. For example, a toy in the nature of a hula hoop has been developed wherein a mass is located inside of the hoop and functions as a noisemaking device. As the hoop is whirled about the midsection of a human, the mass moves in a trajectory similar to the trajectory of a mass propelled by a sling. Other toys and games operating on these principles are disclosed by Ortega, U.S. Pat. No. 3,185,479, Marong U.S. Pat. No. 2,644,270 and Westerberg, U.S. Pat. No. 956,244. In all these devices, a mass, in the form of a sphere, is located in a circular track that is moved to propel the mass about the track. However, the developers of these devices apparently did not realize the possibility of the use of the principles employed in the devices to accelerate a mass that could range from grams to tons to a very high velocity.
In a conventional sling, as schematically illustrated in FIG. 1, mass 1 is attached to cord 2, having a length R. The end of cord 2 remote from mass 1 is rotated about a circular path 3 having a radius r, where R&gt;&gt;r and a center point 4. At different times, mass 1 and cord 2 are located at different positions as designated by dotted lines 1' and 2'. At the end of cord 2 remote from circular path 3, mass 1 moves with rotational velocity V in the circular path. Mass 1 traverses a circle of radius (R.sup.2 +r.sup.2).sup.1/2 at a velocity (V.sub.100 .sup.2 +v.sup.2).sup.1/2 .apprxeq.V, where V.sub..phi. is the velocity component of mass 1 perpendicular to cord 2 and V is the velocity of the mass in the circular path it traverses at the end of cord 2. Since r is much less than R, the velocity ratio V/v.apprxeq.R/r.
The value of V is increased by slowly increasing v while maintaining the phase relationship between mass 1 and the end of cord 2 traversing circular path 3 such that cord 2 remains approximately tangential to the circular path. Work is performed by pulling against the tension of cord 2; the tension on cord 2 is approximately mV.sup.2 /R, where m is the amount of mass of mass 1. The acceleration g.sub..parallel. =V of mass 1 in its circular trajectory is approximately in accordance with: ##EQU1## Hence, the acceleration of mass 1 around the circular path it is traversing, g.sub..parallel., is related to the centrifugal acceleration, g.sub..perp., in accordance with: EQU g.sub..parallel. =g.sub..perp. (r/R).
Because g.sub..parallel. is much less than g.sub..quadbond., mass 1 can reach a high velocity by applying the acceleration g.sub..parallel. for a sufficient length of time. For example, if such a sling were operated in a field-free vacuum using a hypothetical massless cord of high tensile strength, and if the point where cord 2 is connected to path 3 is accelerated slowly to a speed v.sub.max =10 m/sec around inner circle, 3, and the length of cord 2 and the radius of circle r are such that R/r=10.sup.3, then V.sub.max =10 km/sec. Obviously, such a speed cannot be reached since the tensile strength of cord 2 would be exceeded when mass 1 achieved a speed considerably less than 1 km/sec.
The Invention
I have realized that the prior art devices can be modified to provide a method of and apparatus for gradually and smoothly moving preferably accelerating and/or decelerating, a mass located in a track having a path defined by a closed, continuous smooth path. In accordance with my invention, the position of the mass in the track is determined by sensing the mass and/or from preprogrammed data. Movement of the track is controlled so a portion of the track where the mass is determined to be located is moved radially inwardly (for acceleration) or outwardly (for deceleration) along a local radius of curvature of the track.
In a preferred embodiment, the track is relatively rigid and a portion of the track diametrically opposed from the portion of the track where the mass is located is moved in the opposite sense along its local radius of curvature from the direction the track is moved where the mass is located.
To eject the mass from the track, the trajectory of the track and mass is modified so the tube is displaced. In one embodiment, a portion of the track is displaced to have a curvature less than the curvature of the portion of the usual track path. In another embodiment, the trajectory of a portion of the track is modified so that the mass is ejected from the track in a direction having a component at right angles to a plane including the normal circular track it is traversing.
In the preferred embodiment of the invention, the mass is moved in a track having considerably lower than atmospheric pressure to provide a path having low coefficient of friction for the mass traversing the path. The low friction coefficient of the path is preferably augmented by levitating the mass magnetically so that as the mass moves in the track the mass is removed from any mechanical surfaces associated with the track.
In a preferred embodiment, the track is moved by a drive mechanism including a rotating shaft. The speed of the shaft is monotonically changed as the total time spent by the mass moving around the path increases. For acceleration, the speed of the rotating shaft increases monotonically as the operating time of the device progresses; to decelerate the mass, the shaft speed is decreased. In a preferred embodiment, plural rotating shafts distributed about the track are provided and monotonically changed in speed.
The invention has application to accelerating a mass that could range from grams to thousand of kilograms. The invention has particular application to accelerating a mass having a mass value in excess of 1,000 kilograms. In a preferred embodiment, such a mass is slowly accelerated in a closed evacuated guide tube around a circular path of large radius R to a very high velocity V, such as several km/sec., without the use of electric pulse power technology.
The mass is accelerated by a coriolis force that is generated by driving a smooth low speed circular displacement motion of the evacuated guide tube by rotary drive machinery distributed around the circular path. The rotary drive machinery includes synchronized drive rotors that are phased relative to the mass location in response to sensors for the position of the mass around the track. The rotors continuously pull the guide tube, which is preferably circular, inwardly along its radius where the mass is located, i.e., the tube is moved inwardly along its local radius of curvature. The dynamics of the process is similar to that of a conventional sling, but without the cord tensile strength problem that limits conventional slings to accelerating masses to well below 1 km/sec.
The rotary shafts supply a relatively small power to accelerate the guide tube and mass. However, by applying the power to the guide tube and mass over a time interval ranging from seconds to many tens of minutes, the mass can reach an extremely high velocity. Because the power levels are low relative to guns they can be provided by conventional drive motors energized by fossil fuel or electricity. The diameter of the circular path of the guide tube can range from less than a meter to many kilometers depending on the desired velocity of the mass to be accelerated, as well as the magnitude of the mass.
It is, accordingly, an object of the present invention to provide a new and improved method of and apparatus for moving, preferably accelerating, a mass, particularly a heavy mass, at or to high velocities.
Another object of the invention is to provide a new and improved method of and apparatus for decelerating masses.
An additional object of the invention is to provide a new and improved method of and apparatus for moving, preferably accelerating and decelerating, masses by use of principles similar to those used in a sling, but without using a cord that is attached to the mass.
An additional object of the invention is to provide a new and improved method of and apparatus for accelerating a large mass to a high velocity without the need for a large source of electrical pulsed power.
An additional object of the invention is to provide a new and improved method of and apparatus for accelerating and/or decelerating a mass by gradually and smoothly accelerating and/or decelerating the mass along a track defined by a closed, continuous smooth path.
A further object of the invention is to provide a new and improved method of and apparatus for accelerating a large mass to high velocity by using relatively low power sources compared with those required by electrically powered guns.
An additional object of the invention is to provide a new and improved method of and apparatus for accelerating a mass that could range from grams to tons to a velocity in excess of 10 km/sec using conventional rotary power sources, such as internal combustion engines or electric motors.
The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed descriptions of several specific embodiments thereof, especially when taken in conjunction with the accompanying drawings.